package mapper;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpOutputMessage;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;

import static org.mockito.Mockito.spy;

/**
 * @author Arjen Poutsma
 * @author Rossen Stoyanchev
 */
public class MockHttpOutputMessage implements HttpOutputMessage {

    private final HttpHeaders headers = new HttpHeaders();

    private final ByteArrayOutputStream body = spy(new ByteArrayOutputStream());

    private boolean headersWritten = false;

    private final HttpHeaders writtenHeaders = new HttpHeaders();


    @Override
    public HttpHeaders getHeaders() {
        return (this.headersWritten ? HttpHeaders.readOnlyHttpHeaders(this.headers) : this.headers);
    }

    /**
     * Return a copy of the actual headers written at the time of the call to
     * getResponseBody, i.e. ignoring any further changes that may have been made to
     * the underlying headers, e.g. via a previously obtained instance.
     */
    public HttpHeaders getWrittenHeaders() {
        return writtenHeaders;
    }

    @Override
    public OutputStream getBody() throws IOException {
        writeHeaders();
        return body;
    }

    public byte[] getBodyAsBytes() {
        writeHeaders();
        return body.toByteArray();
    }

    public String getBodyAsString(Charset charset) {
        byte[] bytes = getBodyAsBytes();
        return new String(bytes, charset);
    }

    private void writeHeaders() {
        if (this.headersWritten) {
            return;
        }
        this.headersWritten = true;
        this.writtenHeaders.putAll(this.headers);
    }

}
